A variety of rotary couplings has been used for rotatably connecting a tubular riser portion of a spout to a faucet base. Typically these designs comprise a sleeve or snap-ring fitted into a groove in one of the tubular members, with sealing effected by an O-ring secured in a second groove.
Prior art couplings have suffered from various deficiencies. The principal problem is encountered when the retaining or connecting nut securing the two tubular members is over tightened in an effort to overcome the effects of a sloppy fit due to radial clearances between the members. In this situation drastically greater rotational torque is required to rotate the tubular members relative to each other. Additionally, the coupling may be damaged. Still another problem which has been encountered is "spout-slap," which can occur when water pressure surges, e.g., when the faucet is turned on, and is due to axial clearances between the snap-ring and groove.
While it is possible to manufacture the members to close tolerances to reduce the radial and axial clearances and thereby improve the sloppy fit and reduce the "spout-slap," such improvements are usually made at the expense of increased resistance to rotational torque, particularly when the retaining nut is over tightened. Additionally, such improvements involve higher cost of manufacture. Moreover, the nature of the surfaces typically in contact with the snap-ring and O-ring when one tubular member rotates relative to the other often results in excessive wear on the snap-ring and O-ring.